*Broadcast Quality
X-rays that strike a mirror head-on are absorbed. X-rays that hit a mirror at grazing angles are reflected like a pebble skipping across a pond. Thus, X-ray telescope mirrors are shaped like barrels rather than dishes.
[Runtime: 0:25](Animation: CXC/D.Berry) - View Still Photos

2. MIRROR REFLECTIONJava Animation
Photons of visible light enter the telescope at the left, reflect off the parabolic mirror surface and are collected at the focus. Unfortunately, x-ray photons don't reflect as nicely as do visible
photons (click on x-ray to change the photons to x-rays - shown in black). Because of the higher energy of these photons, they are absorbed at the surface of the mirror instead of reflecting. (Animation: CXC/Rutgers)

3. MIRRORS: X-RAY vs. VISIBLE LIGHTJava Animation
X-rays do not reflect off mirrors the same way that visible light does. Because of their high energy, X-ray photons that strike a mirror directly will penetrate into the mirror in much the same way
that bullets aimed directly at a surface will bury themselves in it. (Animation: CXC/Rutgers)